Such a type of device, in which the pre-stressing valve is seated on the lower side of the container directly next to the filling pipe, and the pressurized gas pipe, in the form of a tube, discharges into the gas-filled space immediately above the level of liquid in the container, is already known (GB 625 971).
In this known device, the conveying of pressurized gas into a vessel pressed against the filling pipe while bypassing the return gas pipe is carried out through the separate pressurized gas pipe, so that liquid residues or foam particles from the previous filling process possibly remaining behind in the return gas pipe cannot enter into the vessel. These liquid and foam particles would otherwise favor the release of gas from the liquid subsequently entering into the vessel and lead to an impermissibly great formation of foam. This is particularly critical during the decanting of beverages which have a high carbon dioxide content or which are hot.
In the known device, however, drops of liquid or particles of foam can, because of the above-stated opening in the pressurized gas pipe, easily penetrate into the pressurized gas pipe and accumulate above the pressurized gas valve positioned below. The advantage of a “dry prestressing” that is theoretically present is thereby again nullified.